Topic: CB750 K4 Build - The Cafe Tracer

[Stev-o]

Good progress Budman. 

What are you doing next month? Cool event in Luchenbach you should consider....

http://forums.sohc4.net/index.php?topic=111515.100

[budman]

Interesting. I'll look into it more. My dad has a place in Bandera I could stay at. I'd have to take Friday afternoon off and jam out there. Been a while since I rode the hill country. All I've got is my v-twin bobber. Would that be frowned upon at said event? I could only hang on Saturday. I'd have to get back to Houston on Sunday.

[Stev-o]

Interesting. I'll look into it more. My dad has a place in Bandera I could stay at. I'd have to take Friday afternoon off and jam out there. Been a while since I rode the hill country. All I've got is my v-twin bobber. Would that be frowned upon at said event? I could only hang on Saturday. I'd have to get back to Houston on Sunday.

All bikes are welcome. Saturday is the big day - bike show, live music, BBQ, party! 
We camp right on site....

[budman]

All bikes are welcome. Saturday is the big day - bike show, live music, BBQ, party! 
We camp right on site....

Would be great to get out of Houston for a few days.  The Lone Star Rally is three weeks after that.  I would have to plan wisely.  I'm on a roll with the CB750.  Don't want to spend too much time away.

I got the oil tank cover just about ready to go.  Both covers are ready for the mounting brackets, which I hope to get done next Saturday.

[budman]

I just blasted the swing arm this morning and it had been repainted at least once.  What was underneath was what appears to be almost like a rubberized coating over a red primer.  Is that factory?  If so is that just a swing arm thing?  I know the frame doesn't have a finish like that on it.  It doesn't want to come off with glass beads.  We're setting up a new blast cabinet here at work that is supposed to use aluminum oxide for the media.  It should take off that rubberized coating.

[calj737]

That is not stock. PO must have taken drastic measures to seal and prevent corrosion. Wonder what's hiding under it?

[budman]

I say rubberized because that's how it was reacting when I was blasting it.  It was kind of melting away in places.  It's actually kind of brittle and it's chipping off in some places, but it's really hard.  I wonder if it was painted with Imron or something like that back in the day.  It doesn't appear to be bent or damaged in anyway other than a couple of small gouges, probably from running over something.  I can't see any evidence of excess welding or bodywork.  Whoever owned it before must have wanted to keep it looking pretty.

[budman]

Anyone ever use one of these TC Bros. kickstands?
http://www.tcbroschoppers.com/black-weld-on-kick-stand-for-1-1-8-frame-tubing.html

[budman]

I got the swing arm blasted today.  Whatever was on there was tough and stuck pretty good.  I had to break out the big guns to get it off.  Looks to be in fine shape.  I made some plugs out of old shop rags and duct tape to keep the blast media from damaging the bushing contact surface.

I'll be doing some welding on the frame tomorrow morning and priming parts in the afternoon if all goes to plan.

[Stev-o]

Paint color?

[budman]

Just basic boring old glossy black.

Don't know if you saw my post on that other thread, but I plan on being in Luckenbach on that Saturday.

[Stev-o]

Just basic boring old glossy black.

Don't know if you saw my post on that other thread, but I plan on being in Luckenbach on that Saturday.

I like boring old basic black, semi-gloss is a match of stock.

Great - see you in Luchanbach, I'll have my K4 there as well as my Z1. I'll PM you my number before then.

[budman]

I like boring old basic black, semi-gloss is a match of stock.

Great - see you in Luchanbach, I'll have my K4 there as well as my Z1. I'll PM you my number before then.

10-4

I got the side cover brackets made and welded in place today.  I had to remake the oil tank cover.  It got a little chewed up in the process.  I drilled less holes in the new one.

[budman]

Some parts primed today.  Black epoxy...

[budman]

...then gray filler.

[budman]

I finally got the rotor drilled.  Took a few days.  An hour here, an hour there.  I made a 1:1 paper pattern from my 3D model and stuck it to the face of the rotor with spray adhesive, then marked the holes with a punch.  99 holes and one false start.  I thought it was a punch mark, but it was a small pit in the surface.  I drilled the holes from the back side so the false start is not likely to be noticed.

I also got the wheels primed.  I blasted them at work earlier in the week.

[SOHC4 Cafe Racer Fan]

Nice looking drill job on the rotors. Did you chamfer the holes?

[budman]

Nice looking drill job on the rotors. Did you chamfer the holes?

Yeah, not much of a chamfer, but they're there.

[budman]

So my CB750 is now going to have a little Harley DNA.  The plan was to use the original steel rear fender section to replace the plastic inner fender/mud guard to go with a new café style rear section.  But after cutting the original fender down and trying to weld up the holes in the paper thin metal I decided to find another fender that was going to be easier to work with.  I picked up this Fatboy front fender at a friend's shop today.  I'll pop the dent out, cut it down and shorten it as needed.

I also picked up some black paint today.  I'll be sanding and spraying the wheels and hubs on Saturday.  I've got to get the rear wheel and the swing arm mocked up on the frame so I can mount the new inner fender.

[budman]

First batch of painted parts.  Pretty happy with the results.

[Stev-o]

Looks good Bud.  What paint ya use?

[budman]

PPG Shop-line Acrylic Urethane.  It's an "affordable" brand. I've used it several times with success. I painted my cousin's Sportster with it about four years ago and it still looks brand new.

I see you got the seat.

[Stev-o]

Yes, I got the seat yesterday, thanks again.  It will be for a future K6 project....

[budman]

I got a little ahead of myself and started working on a wiring diagram.  I had a question about adding a start button relay, so I started another thread.
http://forums.sohc4.net/index.php?topic=142098.0
I posted a preliminary wiring diagram in that thread, looking for some feedback.  I haven't gotten any yet so it must be all good.    Just looking for another set of eyes to spot any absurd anomalies and make some recommendations.

[budman]

My new gas tank arrived today.  The one I got with the bike is way beyond usable, so after studying a lot of photos I opted for a Suzuki GT750 tank.  While I really dig a nice CB750 I'm not that crazy about the gas tank, at least for what I'm going after with my build.  The Suzuki has a wide tunnel and the GT750 frame resembles a CB750.  I figured there was a pretty good chance I could make it fit with minimal effort, so I went for it.  The front mounts are the same style and diameter as the Honda tank, but spaced a little wider because of the wider tunnel.  I can probably cut the ones off the CB tank and use them to extend the ones on the GT tank.  The back of the GT tank is about 1/4" shy of fitting over the CB frame.  I had planned on making some knee cut-outs anyway.  A few taps with a body hammer and I should be good.  I might even be able to use the rear mounting tab on the old tank and weld it to the GT tank.  The stock triple trees look they will clear the tank, but I'm ordering some after market trees.  I don't suspect it will be an issue.